• Title/Summary/Keyword: maintenance Strategy

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A Study on Development of the Reliability Evaluation System for VVVF Urban Transit (VVVF 도시철도 차량의 신뢰성 평가 시스템 개발에 관한 연구)

  • Bae Chul-Ho;Kim Sung-Bin;Lee Ho-Yong;Chang Suk-Hwa;Suh Myung-Won
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.5
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    • pp.7-18
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    • 2005
  • Over the past twenty years, the maintenance system has been developed and its importance has been increased. For the effective maintenance of the urban transit, we have developed the maintenance system based on the concept of RCM(Reliability Centered Maintenance). RCM analysis is a systematic approach to developing a cost-effective maintenance strategy based on the various components's reliability of the system in question. It is performed according to process that includes the following steps; definition of function and functional failures of the systems, construction of RB D(Reliability Block Diagram), performance of FMEA(Failure Modes & Effects Analysis) and calculation of the reliability index. The final process of RCM is to determine appropriate failure maintenance strategies. This paper aims to define the procedure of maintenace based on the concept of RCM for urban transit. The key for a successful maintenance system is an automated scheduling to the maximum extent possible and timely executions. The developed system issues maintenance plan and repair request based on analyzed data and maintenance experience.

Pemetrexed Continuation Maintenance versus Conventional Platinum-Based Doublet Chemotherapy in EGFR-Negative Lung Adenocarcinoma: Retrospective Analysis

  • Paik, Seung Sook;Hwang, In Kyoung;Park, Myung Jae;Lee, Seung Hyeun
    • Tuberculosis and Respiratory Diseases
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    • v.81 no.2
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    • pp.148-155
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    • 2018
  • Background: Although targeted therapy and immuno-oncology have shifted the treatment paradigm for lung cancer, platinum-based combination is still the standard of care for advanced non-small cell lung cancer (NSCLC). Pemetrexed continuation maintenance therapy has been approved and increasingly used for patients with nonsquamous NSCLC. However, the efficacy of this strategy has not been proven in patients without driving mutations. The objective of this study was to compare the clinical benefit of pemetrexed continuation maintenance to conventional platinum-based doublet in epidermal growth factor receptor (EGFR)-negative lung adenocarcinoma. Methods: A total of 114 patients with EGFR-negative lung adenocarcinoma who were treated with platinum doublet were retrospectively enrolled. We compared the survival rates between patients received pemetrexed maintenance after four-cycled pemetrexed/cisplatin and those received at least four-cycled platinum doublet without maintenance chemotherapy as a first-line treatment. Results: Forty-one patients received pemetrexed maintenance and 73 received conventional platinum doublet. Median progression-free survival (PFS), which was defined as the time from the day of response evaluation after four cycles of chemotherapy to disease progression or death, was significantly higher in the pemetrexed maintenance group compared to conventional group (5.8 months vs. 2.2 months, p<0.001). Median overall survival showed an increasing trend in the pemetrexed maintenance group (22.3 months vs. 16.1 months, p=0.098). Multivariate analyses showed that pemetrexed maintenance chemotherapy was associated with better PFS (hazard ratio, 0.73; 95% confidence interval, 0.15-0.87). Conclusion: Compared to conventional platinum-based chemotherapy, premetrexed continuation maintenance treatment is associated with better clinical outcome for the patients with EGFR wild-type lung adenocarcinoma.

Analysis of Chinese ASP Market and Implications for Korean Firm's Chinese Market Entry Strategy (중국 ASP 시장 분석과 한국 기업의 진입 전략에 대한 시사점)

  • Kim Dae-Ho;Kwon Sun-Dong
    • Journal of Information Technology Applications and Management
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    • v.13 no.1
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    • pp.95-116
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    • 2006
  • Many SMEs have adopted ASP models which have brought various benefits to SMEs such as decreasing the total cost, using new IT technology, enhancing the maintenance, and implementing the information systems rapidly. Ministry of Information and Communication had implemented the ASP diffusion project for the ASP venders and SMEs between 2001 and 2003. As results of this project, various industries adopted the ASP applications of which the performance was enhanced, and then the competitiveness of the ASP vendors in Korea was increased. The purpose of this study is to make a strategy of the penetration into China market for ASP services which have competitive advantages. This study uses various research methods such as questionnaire survey, visiting SMEs in china and making interviews. This study shows the current status of Chines ASP market, the several cases of using ASP services, and questionnaire analyses(service recognition, service requirement and factors and infrastructure, business environment and supporting organizations etc) of ASP demand. And finally this study proposes several strategic considerations in entering China market and suggests several support policies for supporting Korean ASPs.

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Cooperative Strategies and Swarm Behavior in Distributed Autonomous Robotic Systems Based on Artificial Immune System (인공 면역계 기반 자율분산로봇 시스템의 협조 전략과 군행동)

  • Sim, Kwee-Bo;Lee, Dong-Wook;Sun, Sang-Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.12
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    • pp.1079-1085
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    • 2000
  • In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). An immune system is the living bodys self-protection and self-maintenance system. these features can be applied to decision making of the optimal swarm behavior in a dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody, and control parameter as a T-cell, respectively. When the environmental condition (antigen) changes, a robot selects an appropriate behavior strategy (antibody). And its behavior strategy is stimulated and suppressed by other robots using communication (immune network). Finally, much stimulated strategy is adopted as a swarm behavior strategy. This control scheme is based on clonal selection and immune network hypothesis, and it is used for decision making of the optimal swarm strategy. Adaptation ability of the robot is enhanced by adding T-cell model as a control parameter in dynamic environments.

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Cooperative Strategies and Swarm Behavior in Distributed Autonomous Robotic Systems based on Artificial Immune System

  • Sim, Kwee-bo;Lee, Dong-wook
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.7
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    • pp.591-597
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    • 2001
  • In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control school is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

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Development of the Database System for Maintenance of Civil Facilities in Urban Transit (도시철도 토목시설물 유지관리를 위한 데이터베이스 구축방안 연구)

  • Shin Jeong-Ryol;Kim Gil-Dong;Lee Woo-Dong;Park Seo-Young
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.1108-1113
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    • 2004
  • While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of civil facilities among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about civil facilities through standardizing technology resources are described in this paper.

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Development of the Database System for Maintenance of Track System in Urban Transit (도시철도 선로시설물 유지관리를 위한 데이터베이스 구축방안 연구)

  • Shin Jeong-Ryol;Lee Woo-Dong;Kim Gil-Dong;Park Seo-Young
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.935-941
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    • 2004
  • While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of track system among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about track. system through standardizing technology resources are described in this paper.

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Development of the Database System for Maintenance of Station Facilities in Urban Transit (도시철도 역설비 시설물 유지관리를 위한 데이터베이스 구축 방안 연구)

  • Lee Woo-Dong;Shin Jeong-Ryol;Lee Ho-Yong;Ahn Tae-Ki
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.1221-1226
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    • 2004
  • While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of station facilities among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about station facilities through standardizing technology resources are described in, this paper.

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Behavioral Strategies for Weight Loss Maintenance (체중감량 이후 장기적인 유지를 위한 다양한 행동전략)

  • Young Hye Cho
    • Archives of Obesity and Metabolism
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    • v.2 no.1
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    • pp.6-10
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    • 2023
  • Compensatory changes in energy consumption and neuro-hormonal changes following weight loss make it difficult to maintain the reduced weight and may cause weight regain. Therefore, establishing a long-term weight control plan and strategy starting from the initial weight loss period is necessary. Both the patient and doctor should know that weight loss cannot occur continuously, and that maintaining weight after the weight loss period is the basic course of obesity treatment. No single dietary pattern is effective for weight maintenance, and a variety of dietary control methods - such as calorie restriction and healthy proportions of carbohydrates, proteins, fats, and meal replacements - should be used to target an integrated and healthy dietary habit. An increase in physical activity is needed for weight loss and maintenance; however, rather than recommending an excessive amount of exercise, it is better to set realistic and long-term achievable goals. It is necessary to reset the goal according to the patient's weight maintenance stage and continuously apply behavioral therapies, such as self-monitoring and stress management. In previous studies, since the degree of weight loss and changes in behavioral patterns over the course of one year were important factors in maintaining long-term weight loss, obesity therapists should closely examine patient data and behavioral patterns across a period of one year and actively intervene when needed.

The Model to Generate Optimum Maintenance Scenario for Steel Bridges considering Life-Cycle Cost and Performance (강교량의 최적 유지관리 시나리오 선정 모델)

  • Park, Kyung Hoon;Lee, Sang Yoon;Kim, Jung Ho;Cho, Hyo Nam;Kong, Jung Sik
    • Journal of Korean Society of Steel Construction
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    • v.18 no.6
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    • pp.677-686
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    • 2006
  • In this paper, a more practical and realistic method is proposed to establish the lifetime optimum maintenance strategies of the deteriorating bridges considering the life-cycle performance as well as life-cycle cost. The genetic algorithm is applied to generate the set of maintenance scenarios that is the multi-objective combinatorial optimization problem related to lifetime performance and cost as separate objective functions, and the technique to select optimum tradeoff maintenance scenario is presented. Optimum maintenance scenarios could be generated not only at the individual member level but also at the system level of the bridge. Through the analytical results of applying the proposed methodology to the existing bridge, it is expected that the methodology will be effectively used to determine the optimum maintenance strategy for introducing a real preventive maintenance system and overcoming the limits of existing maintenance methods.